title: Incidence, Paris classification, and follow-up in a nationwide incident cohort of pediatric patients with inflammatory bowel disease.
abstract: OBJECTIVE
  The aim of the study was to evaluate the incidence, baseline disease characteristics, and disease location based on the Paris classification in pediatric inflammatory bowel disease (IBD) in the Hungarian nationwide inception cohort. In addition, 1-year follow-up with therapy was analyzed.
  
  
  METHODS
  From January 1, 2007 to December 31, 2009, newly diagnosed pediatric patients with IBD were prospectively registered. Twenty-seven pediatric gastroenterology centers participated in the data collection ensuring the data from the whole country. Newly diagnosed patients with IBD younger than 18 years were reported. Disease location was classified according to the Paris classification.
  
  
  RESULTS
  A total of 420 patients were identified. The incidence rate of pediatric IBD was 7.48/10⁵ (95% confidence interval [CI] 6.34/10⁵-8.83/10⁵). The incidence for Crohn disease (CD) was 4.72/10⁵ (95% CI 3.82-5.79), for ulcerative colitis (UC) 2.32/10⁵ (95% CI 1.71-3.09), and for IBD-unclassified 0.45/10⁵ (95% CI 0.22-0.84). Most common location in CD was L3 (58.7%); typical upper gastrointestinal abnormalities (ulcer, erosion and aphthous lesion) were observed in 29.9%. Extensive colitis in patients with UC (E4, proximal to hepatic flexure) was the most common disease phenotype (57%), whereas only 5% of children had proctitis. A total of 18.6% of patients had ever severe disease (S1). Frequency of azathioprine administration at diagnosis was 29.5% in patients with CD, and this rate increased to 54.6% (130/238) at 1-year follow-up. In UC, only 3.3% received azathioprine initially, and this rate elevated to 22.5% (25/111). Use of corticosteroid decreased from 50% to 15.3% in patients with UC. Rate of bowel resection in patients with CD during the first year of follow-up was 5%.
  
  
  CONCLUSIONS
  The incidence of pediatric IBD in Hungary was among the higher range reported. This is the first large, nationwide incident cohort analyzed according to the Paris classification, which is a useful tool to determine the characteristic pediatric CD phenotype.
authors.affiliation: 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
authors.forename: Katalin E
authors.initials: KE
authors.lastname: Müller
authors.forename: Péter L
authors.initials: PL
authors.lastname: Lakatos
authors.forename: András
authors.initials: A
authors.lastname: Arató
authors.forename: Judit B
authors.initials: JB
authors.lastname: Kovács
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Várkonyi
authors.forename: Dániel
authors.initials: D
authors.lastname: Szűcs
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Szakos
authors.forename: Enikő
authors.initials: E
authors.lastname: Sólyom
authors.forename: Márta
authors.initials: M
authors.lastname: Kovács
authors.forename: Marianne
authors.initials: M
authors.lastname: Polgár
authors.forename: Éva
authors.initials: É
authors.lastname: Nemes
authors.forename: Ildikó
authors.initials: I
authors.lastname: Guthy
authors.forename: István
authors.initials: I
authors.lastname: Tokodi
authors.forename: Gergely
authors.initials: G
authors.lastname: Tóth
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Horváth
authors.forename: András
authors.initials: A
authors.lastname: Tárnok
authors.forename: Noémi
authors.initials: N
authors.lastname: Csoszánszki
authors.forename: Márta
authors.initials: M
authors.lastname: Balogh
authors.forename: Noémi
authors.initials: N
authors.lastname: Vass
authors.forename: Piroska
authors.initials: P
authors.lastname: Bódi
authors.forename: Antal
authors.initials: A
authors.lastname: Dezsőfi
authors.forename: László
authors.initials: L
authors.lastname: Gárdos
authors.forename: Eva
authors.initials: E
authors.lastname: Micskey
authors.forename: Mária
authors.initials: M
authors.lastname: Papp
authors.forename: Áron
authors.initials: Á
authors.lastname: Cseh
authors.forename: Dolóresz
authors.initials: D
authors.lastname: Szabó
authors.forename: Péter
authors.initials: P
authors.lastname: Vörös
authors.forename: Gabor
authors.initials: G
authors.lastname: Veres
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy; D003424:Crohn Disease / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006814:Hungary / Q000453:epidemiology; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D010818:Practice Patterns, Physicians'; D011446:Prospective Studies; D012042:Registries; D012720:Severity of Illness Index
chemical_list: D000305:Adrenal Cortex Hormones; D000894:Anti-Inflammatory Agents, Non-Steroidal; D007166:Immunosuppressive Agents